A substrate polishing apparatus polishes a surface of a substrate by pressing the substrate against a polishing pad attached to a turntable. As a surface condition of the polishing pad may be changed by polishing the substrate, the substrate polishing apparatus has a dresser that dresses the surface of the polishing pad to perform dressing on the surface so that the surface becomes suitable for polishing.
The dressing may be performed in parallel with processing of the substrate (so-called in-situ dressing), or may be performed after processing a substrate and before processing the next substrate (so-called ex-situ dressing). Further, there is dressing that peels a surface layer of a new polishing pad so that the polishing pad easily holds polishing liquid (so-called pad break-in process).
In any dressing, it may not be possible to obtain the same dressing result even when the dressing is performed under a constant control condition (recipe). Therefore, it is desirable to monitor a force when the dresser dresses the polishing pad.
In view of the problem as described above, it is desirable to provide a substrate polishing apparatus that can monitor a force when the dresser dresses the polishing pad.
A substrate polishing apparatus according to one embodiment includes: a turntable for supporting a polishing pad; a dresser that dresses the polishing pad; a dresser drive module that presses the dresser against the polishing pad and rotates the dresser; a support member that supports the dresser drive module; and a plurality of force sensors which are provided between the dresser drive module and the support member, each of the plurality of force sensors outputting information related to each of forces in three axis directions.
A substrate polishing apparatus according to another embodiment includes: a turntable for supporting a polishing pad; a dresser that dresses the polishing pad; a dresser drive module that presses the dresser against the polishing pad and rotates the dresser; a support member that supports the dresser drive module; a plurality of force sensors which are provided between the dresser drive module and the support member, each of the plurality of force sensors outputting third information related to a force component in a direction from the polishing pad to the dresser; and a second pad dressing force calculator that calculates a force for the dresser to dress the polishing pad, based on the third information outputted from the plurality of force sensors and distances between each of the plurality of force sensors and a dressing surface of the dresser.